ATGBICS Universal QSFP-DD 400GBase Loopback Testing module is used for testing QSFP28 transceiver ports in board level test. By substituting for a full-featured QSFP28 transceiver, the electrical loopback provides a cost effective low loss method for QSFP28 port testing. Our product is packaged in a standard MSA housing compatible with all QSFP28 ports. Transmit data from the host is electrically routed (internal to the loopback module) to the receive data outputs and back to the host.  This product operates within an industrial temperature range.